From b15fc5caafaac09951f62d90f3f31b69b8535370 Mon Sep 17 00:00:00 2001
From: Earl Warren <contact@earl-warren.org>
Date: Tue, 24 Oct 2023 19:40:35 +0200
Subject: [PATCH] use ref instead of sha

---
 cascading-pr.sh | 30 +++++++++---------------------
 1 file changed, 9 insertions(+), 21 deletions(-)

diff --git a/cascading-pr.sh b/cascading-pr.sh
index 08c44a5..bb5a11b 100755
--- a/cascading-pr.sh
+++ b/cascading-pr.sh
@@ -147,35 +147,25 @@ function pr_number() {
     pr $1 | jq --raw-output .number
 }
 
-function pr_sha() {
-    pr_get $1
-    merged=$(pr $1 | jq --raw-output .merged)
-    if "$merged"; then
-	pr $1 | jq --raw-output .merge_commit_sha
-    else
-	pr $1 | jq --raw-output .head.sha
-    fi
-}
-
 function pr_merged() {
     pr_get $1
     pr $1 | jq --raw-output .merged
 }
 
 function upsert_clone() {
-    local direction=$1 ref="$2" sha="$3" clone=$4
+    local direction=$1 ref="$2" clone=$3
 
     if ! test -d $TMPDIR/$direction; then
 	git -c credential.helper="store --file=$TMPDIR/$direction.git-credentials" clone $clone $TMPDIR/$direction
     fi
     (
 	cd $TMPDIR/$direction
-	if test "$ref"; then
-	    git switch -c $direction origin/$ref
-	fi
-	if test "$sha"; then
-	    git switch -c $direction $sha
+	if [[ "$ref" =~ ^refs/ ]] ; then
+	    git fetch origin +$ref:$ref
+	else
+	    ref=origin/$ref
 	fi
+	git checkout -b $direction $ref
 	git config credential.helper "store --file=$TMPDIR/$direction.git-credentials"
 	git config user.email cascading-pr@example.com
 	git config user.name cascading-pr
@@ -212,8 +202,8 @@ function wait_destination_ci() {
 }
 
 function update() {
-    upsert_clone origin "${options[origin_head]}" "${options[origin_sha]}" ${options[origin_clone]}
-    upsert_clone destination "${options[destination_head]}" "${options[destination_sha]}" ${options[destination_clone]}
+    upsert_clone origin "${options[origin_head]}" ${options[origin_clone]}
+    upsert_clone destination "${options[destination_head]}" ${options[destination_clone]}
     (
 	cd $TMPDIR/origin
 	${options[update]} $TMPDIR/destination $TMPDIR/destination-pr.json $TMPDIR/origin-pr.json
@@ -243,8 +233,7 @@ function finalize_options() {
     options[origin_scheme]=$(scheme ${options[origin_url]})
     options[origin_host_port]=$(host_port ${options[origin_url]})
     set_clone origin
-    options[origin_head]=
-    options[origin_sha]=$(pr_sha origin)
+    options[origin_head]=refs/pull/${options[origin_pr]}/head
     options[destination_api]=${options[destination_url]}/api/v1/repos/${options[destination_repo]}
     options[destination_scheme]=$(scheme ${options[destination_url]})
     options[destination_host_port]=$(host_port ${options[destination_url]})
@@ -252,7 +241,6 @@ function finalize_options() {
     options[destination_base]=${options[destination_branch]}
     : ${options[prefix]:=${options[origin_repo]}}
     options[destination_head]=${options[prefix]}-${options[origin_pr]}
-    options[destination_sha]=
 }
 
 function run() {